/*******************************************************************************
 * Copyright 2017 Bstek
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License.  You may obtain a copy
 * of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations under
 * the License.
 ******************************************************************************/
package com.bstek.ureport.utils;

import java.awt.Graphics2D;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;

import javax.imageio.ImageIO;

import org.apache.commons.io.IOUtils;
import org.springframework.util.Base64Utils;

import com.bstek.ureport.exception.ReportComputeException;
import com.bstek.ureport.image.ChartImageProcessor;
import com.bstek.ureport.image.ImageProcessor;
import com.bstek.ureport.image.ImageType;
import com.bstek.ureport.image.StaticImageProcessor;

/**
 * @author Jacky.gao
 * @since 2017年3月20日
 */
public class ImageUtils {

	private static Map<ImageType, ImageProcessor<?>> imageProcessorMap = new HashMap<ImageType, ImageProcessor<?>>();

	static {

		StaticImageProcessor staticImageProcessor = new StaticImageProcessor();
		imageProcessorMap.put(ImageType.image, staticImageProcessor);
		ChartImageProcessor chartImageProcessor = new ChartImageProcessor();
		imageProcessorMap.put(ImageType.chart, chartImageProcessor);
	}

	public static InputStream base64DataToInputStream(String base64Data) {
		byte[] bytes = Base64Utils.decodeFromString(base64Data);
		ByteArrayInputStream inputStream = new ByteArrayInputStream(bytes);
		return inputStream;
	}

	@SuppressWarnings("unchecked")
	public static String getImageBase64Data(ImageType type, Object data, int width, int height) {
		ImageProcessor<Object> targetProcessor = (ImageProcessor<Object>) imageProcessorMap.get(type);
		if (targetProcessor == null) {
			throw new ReportComputeException("Unknow image type :" + type);
		}
		InputStream inputStream = targetProcessor.getImage(data);
		try {
			if (width > 0 && height > 0) {
				BufferedImage inputImage = ImageIO.read(inputStream);
				BufferedImage outputImage = new BufferedImage(width, height, Transparency.TRANSLUCENT);
				Graphics2D g = outputImage.createGraphics();
				g.drawImage(inputImage, 0, 0, width, height, null);
				g.dispose();
				ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
				ImageIO.write(outputImage, "png", outputStream);
				inputStream = new ByteArrayInputStream(outputStream.toByteArray());
			}
			byte[] bytes = IOUtils.toByteArray(inputStream);
			return Base64Utils.encodeToString(bytes);
		} catch (Exception ex) {
			throw new ReportComputeException(ex);
		} finally {
			IOUtils.closeQuietly(inputStream);
		}
	}
}
